Method and device for long-range track seeking control in an optical storage system

Abstract

A device for long-range track seeking control in an optical storage system includes a controller that calculates a track displacement count based on initial and target track positions of an optical pickup, a calculator that calculates a motor actuation count based on the track displacement count and an initial track crossing parameter, a control signal generator that generates a control signal in accordance with the motor actuation count, a driver that actuates the sled motor so as to move the optical pickup in response to the control signal, and a heuristic calibrating unit that is operable so as to revise the initial track crossing parameter in accordance with a residual track count calculated from the target track position and a current track position resulting from movement of the optical pickup.

1 . A method for long-range track seeking control in an optical storage system that is loaded with an optical disc and that includes an optical pickup and a sled motor for moving the optical pickup from an initial track position of the optical disc to a target track position of the optical disc, said method comprising the steps of: 
 a) calculating a track displacement count based on the initial and target track positions;    b) calculating a motor actuation count based on the track displacement count and an initial track crossing parameter associated with the sled motor, the track crossing parameter defining a number of tracks of the optical disc crossed during an actuation cycle of the sled motor;    c) actuating the sled motor according to the motor actuation count so as to move the optical pickup;    d) after moving the optical pickup, calculating a residual track count based on a current track position and the target track position of the optical disc; and    e) revising the initial track crossing parameter in accordance with the residual track count.    
   
   
       2 . The method as claimed in  claim 1 , wherein, in step e), the initial track crossing parameter is revised only when the residual track count does not fall within a tolerable range.  
   
   
       3 . The method as claimed in  claim 1 , wherein the initial track crossing parameter is dependent upon magnitude of the track displacement count.  
   
   
       4 . The method as claimed in  claim 1 , wherein, in step e), the initial track crossing parameter is increased with reference to the residual track count when an actual track displacement from the initial track position to the current track position is larger than a predicted track displacement, and is decreased with reference to the residual track count when the actual track displacement is smaller than the predicted track displacement.  
   
   
       5 . A device for long-range track seeking control in an optical storage system that is loaded with an optical disc and that includes an optical pickup and a sled motor for moving the optical pickup from an initial track position of the optical disc to a target track position of the optical disc, said device comprising: 
 a controller adapted to be coupled to the optical storage system so as to receive the initial and target track positions there from and operable so as to calculate a track displacement count based on the initial and target track positions;    a calculator coupled to said controller and operable so as to calculate a motor actuation count based on the track displacement count and an initial track crossing parameter associated with the sled motor, the track crossing parameter defining a number of tracks of the optical disc crossed during an actuation cycle of the sled motor;    a control signal generator coupled to said calculator and operable so as to generate a control signal in accordance with the motor actuation count;    a driver coupled to said control signal generator and adapted to actuate the sled motor so as to move the optical pickup in response to the control signal from said control signal generator; and    a heuristic calibrating unit coupled to said calculator and operable so as to revise the initial track crossing parameter in accordance with a residual track count calculated from the target track position and a current track position resulting from movement of the optical pickup.    
   
   
       6 . The device as claimed in  claim 5 , wherein said heuristic calibrating unit is configured to revise the initial track crossing parameter only when the residual track count does not fall within a tolerable range.  
   
   
       7 . The device as claimed in  claim 5 , wherein the initial track crossing parameter is dependent upon magnitude of the track displacement count.  
   
   
       8 . The device as claimed in  claim 5 , wherein said heuristic calibrating unit increases the initial track crossing parameter with reference to the residual track count when an actual track displacement from the initial track position to the current track position is larger than a predicted track displacement, and decreases the initial track crossing parameter with reference to the residual track count when the actual track displacement is smaller than the predicted track displacement.  
   
   
       9 . The device as claimed in  claim 5 , wherein said controller is further operable so as to calculate and provide the residual track count to said heuristic calibrating unit.